1. Field of the Invention
The present invention relates to a driving support apparatus configured to receive externally transmitted information transmitted from a communication device external to an own vehicle, and to give a notification for driving support to a driver based on the externally transmitted information and own vehicle information.
2. Description of the Related Art
Hitherto, there has been known a driving support apparatus configured to receive externally transmitted information, which is information transmitted from a roadside device, and to support driving of the driver based on the externally transmitted information and own vehicle information. For example, in a driving support apparatus proposed in Japanese Patent Application Laid-open No. 2004-171459, traffic light information transmitted from a traffic light is received by an in-vehicle communication device. The traffic light information includes information on a lighting state and a lighting period of the traffic light. The driving support apparatus is configured to calculate a period until the lighting state of the traffic light changes based on the traffic light information when the own vehicle is located near the traffic light, and to display this period on a display device. As a result, the driver can drive while recognizing the period until the lighting state of the traffic light changes.
The system configured to use the in-vehicle communication device to receive the externally transmitted information transmitted from the roadside device, and to use the information for the driving support for the driver in this way is referred to as vehicle-infrastructure cooperative system. The externally transmitted information transmitted from the roadside device includes vehicle detection information on vehicles detected in a vicinity of an intersection and the traffic light information on lighting of a traffic light.
The driving support apparatus is configured to operate a notification device so as to give a notification for the driving support when a support condition for providing a service for the driving support to the driver is satisfied based on the externally transmitted information and own vehicle information (information representing a position and a driving state of the own vehicle). For example, the driving support apparatus estimates whether the driver overlooks a red traffic signal based on the traffic light information and the own vehicle information. The driving support apparatus is configured to sound a buzzer, and to display characters, “Caution: Red Signal”, a symbol, and the like on a screen of the display device when such a condition that the driver is supposed to have overlooked a red traffic signal is satisfied. This can cause the driver to pay attention to the traffic light.
Incidentally, a collision avoidance support system is known as one of the driving support apparatus independently of the vehicle-infrastructure cooperative system. The collision avoidance support system is configured to detect an obstacle ahead of the own vehicle through a sensor, e.g., a radar, installed on the own vehicle, determine that the support condition is satisfied when such a condition that the own vehicle is highly likely to collide with the obstacle is satisfied, and prompt the driver to carry out a collision avoidance operation through the display device and the buzzer.
However, when both the vehicle-infrastructure cooperative system and the collision avoidance support system are installed on the vehicle, the following problem occurs. For example, the support condition determined by the vehicle-infrastructure cooperative system and the support condition determined by the collision avoidance support system may be simultaneously satisfied. In this case, when the support information provided by the vehicle-infrastructure cooperative system and the support information provided by the collision avoidance support system are simultaneously displayed, the driver has difficulty in instantaneously determining an action to take.
The support information provided by the collision avoidance support system is information released when the state in which the own vehicle collides with an obstacle is imminent, and is an alarm of instructing the driver to immediately carry out the collision avoidance operation, e.g., a brake operation.
On the other hand, the support information provided by the vehicle-infrastructure cooperative system is information of notifying the driver of the state to which the driver needs to pay attention at an intersection, and is different from the information of strongly prompting the drive to take an action.
Thus, when the support information by the vehicle-infrastructure cooperative system and the support information by the collision avoidance support system are simultaneously provided, the information (instruction of prompting the collision avoidance operation, e.g., the brake operation) that needs to be notified to the driver may not be appropriately transmitted to the driver.